This of course is no surprise, since in the real history upon which this series is based - but doesn't always adhere to - Masters and Johnson were, in fact, married. In the series, it took long enough for the two to get there, and this made the ending satisfying in a long overdue way.
But in many ways, the Art and Nancy story was more compelling, and certainly more surprising, since the couple, as far as I know, are fictitious. Their relationship - to Masters and Johnson - but, more important, to themselves - provided one of the most vivid tableaus on television of a couple who know each other very well, but not well enough, and in the end founder on about as fundamental a difference in a couple you could find.
Their ending was heartbreaking in a way that nothing between Masters and Johnson, certainly this season, has been, and not much on previous seasons, either. Kudos to Betty Gilpin and Jeremy Strong each for quietly fabulous and deeply memorable performances.
Looking forward to next season, it will be fun to see Masters and Johnson and their life together, not only outside of the lab, but publicly together, under one roof, in a way we haven't seen them. Meeting in smoky places (one of my favorite songs from the early 1960s - actually, of all time, though I'm not sure why) and in hotel rooms can get tedious (not the song - see below for the video), and there are no doubt great scenes in store in the story ahead for this couple.
It will also be good to see how their pioneering work fares in the 1970s - which, come to think of it, was when I first became admiringly aware of their work. In any case, here's a tip of the hat to those smoky places.